It is known that the properties of polymers produced by the electrodeposition of aniline is strongly dependent on the experimental conditions used. In these electrochemical methods two main steps can occur, the (1) nucleation process and (2) the growth of the polymeric film. We have observed that the nucleation step may well dictate the subsequent nanostructure, i.e. the film growth and its nano-morphology, and may be dependent on several factors, such as working electrode and the electrochemical conditions employed. To date no systematic studies have been reported in the literature regarding the controllable synthesis of nanostructures of electroactive organic polymers using electrochemical methods. In this work we have established conditions for the controllable electrochemical synthesis of nanostructures of polyanilines. PANI nanostructures was synthesized by cyclic voltammetry in the form of dispersed nanoparticles (diameter ranging from 50 to 80 nm) and of nanofibers with diameter in the range of 40-100nm and length up to 4 m, demonstrating that under selected conditions nanostructures of polyaniline can be obtained in a controllable manner by electrochemical methods.